Plenum construction

ABSTRACT

A plenum construction for receiving air from an air treating unit and distributing same to a plurality of zones to be treated. The plenum construction comprises a housing having wall means therein defining at least a pair of adjacent chambers, each having an entry portion and a discharge portion, with an inclined wall forming a common wall between the chambers and with the length of each discharge portion being substantially equal to the sum of the lengths of the entry portions of the adjacent chambers.

United States Patent 11 1 Qoplin I Sept. 11, 1973 PLENUM CONSTRUCTION 3,254,701 6/1966 Thomason 62 263 x 5 I t z F W [7 nven or Jess Lee Cophn, ort orth, Tex Primary Examiner Meyer Peru [73] Assignee: Lennox Industries Inc., Assistant ExaminerRonald C. Capossela Marshalltown, Iowa AttorneyA. W. Molinare et al.

22 Fl (1: D 27 1971 l 1 cc 57 ABSTRACT [21] Appl 212392 A plenum construction for receiving air from an air treating unit and distributing same to a plurality of [52] us. Cl. 98/40 R, 138/39 zones to be treated- The ple m c nstr i n com- [51] Int. Cl F24f 7/00 prises a housing having wall means therein defining at 58 Field 6: Search 137/561 A; 138/37, least a p of adjacent chambers. each having an entry 138/39; 98/32, 40 R, 40 C, 94; 62/263 portion and a discharge portion, with an inclined wall forming-a common wall between the chambers and [56] References Ci d with the length of each discharge portion being substantially equal {0 th sum of the lengths Of the entry 3,482,506 12 1969 Bruns 98/40 c pomms of the adjacent chambers Kramer l 62/263 8 Claims, 10 Drawing Figures Patented Sept. 11, 1973 3 Sheets-Sheet l Patented Sept. 11, 1973 FIG. 6

ISI/

FIG. 7

Patented Sept. 11, 1973 3,757,665

3 Sheets-Sheet 5 PLENUM CONSTRUCTION BACKGROUND OF THE INVENTION This invention relates, to a plenum construction and more particularly an improved plenum construction for receiving air from an air treating unit and distributing same to a plurality of zones to be treated.

The roof top air treating unit has gained wide acceptance in a number of commercial uses, for example schools, medical centers, motels and restaurants. The air treating unit is mounted on a roof such that air from the zones to be treated may enter an opening therein, be suitably processed (heating, cooling, or ventilating),

and then discharged through a suitable opening to a plenum construction from which the air is communicated by ducts to the zones to be treated. The outlet from the air treating unit is of relatively standardized size as is the inlet to the plenum construction, which has an opening complementary to that of the outlet of the air treating unit. Where only a few zones are to be treated, the spaces for the compartments in the plenum construction provided by parallel transverse divider walls may be rather large, however, as the number of zones to be treated increases, the number of compartments correspondingly increases, reducing compartment width and making difficult the attachment of the large number of ducts required to each of the outlets from the plenum. If the outlets are too small in crosssection, there will be inadequate air distribution to each zone to provide the desired heating, cooling or ventilating. There may be a loss of velocity pressure of g the air. This problem can be overcome by running the circulating fan within the air treating unit more rapidly, however, an increase in fan speed to attain desired air movement would be attended by an increased fan noise. In some instances, it would be necessary to provide a larger fan to obtain the necessary air movement to each zone to be treated. This undesirably iricreases costs.

One solution suggested for the problem of srhall outlet openings was .to stagger the compartments whereby the outlet opening would be substantially the width of two adjacent compartments. However, the divider walls were provided by vertically extending sections. An undesirable velocity pressure loss was found to exist in such construction.

In some installations where the air treating unit may be close to one of the side walls of the building or some other building obstruction, the plenum construction might necessarily be positioned too close to the side wall of the building or to the obstruction to permit ducts to be connected to both sides of the plenum construction. This would limit the number of air distribution ducts that might be secured to the plenum construction and thus could limit the utility of the particular plenum construction.

An object of the present'invention is to provide an improved plenum construction wherein the deficiencies and disadvantages of prior constructions is obviated.

Another object of the present invention is to provide an improved plenum construction for receiving air from an air treating unit and distributing same to a plurality of zones so as to provide adequate air distribution to each zone with a minimum velocity pressure loss.

Yet another object to the present invention is to provide a plenum construction for receiving air from an air treating unit and distributing same to a plurality of zones which incorporates a plurality of wall means within the housing of the plenum construction, constructed and arranged to define adjacent chambers, said wall means including an inclined wall forming a common wall between adjacent chambers, each chamber including an entry portion and a discharge portion, 'with the length of each discharge portion being substantially equal to the sum of the lengths of the entry portions of the adjacent chambers.

Still another object of the present invention is to provide an improved plenum construction comprised of a housing having wall means including inclined walls therein defining chambers so constructed and arranged that there is minimal velocity pressure loss as the air passes through each chamber in a streamlined flow path, whereby the blower for moving the air can run slower and quieter in operation than for a comparable conventional plenum. Other objects and advantages of the present invention will become more apparent hereafter.

DESCRIPTION OF THE DRAWING There is illustrated in the attached drawing presently preferred embodiments of the present invention, wherein likenumberals refer to like elements in the different views, and wherein:

FIG. 1 is a perspective view of a typical roof mounted air treating unit installation, with portions of the roof top being broken away to illustrate the plenum construction and ducts secured thereto;

FIG. 2 is a perspective view of an improved plenum construction embodying principles of the present invention;

FIG. 3 is a top view of the plenum construction of FIG. 2;

FIG. 4 is a side view of the plenum construction of FIG. 2;

FIG. 5 is a bottom view of the plenum construction 2;

FIG. 6 is a cross-sectional view of the plenum construction taken generally along line 66 of FIG. 3;

FIG. 7 is a cross-sectional view similar to FIG. 6 of a modified plenum construction;

FIG. 8 is an exploded perspective view of the plenum construction of FIG. 2;

FIG. 9 is a perspective view of the plenum construction of FIG. 1; and

FIG. 10 is a detail perspective view of the wall means of the plenum construction of FIG. 9.

DETAILED DESCRIPTION OF THE PRESENT INVENTION Referring to FIG. I, there is illustrated an air treating unit 10 mounted on the roof 12 of a building in a conventional fashion. The air treating unit 10 may be of the 'type illustrated in Norris et al. US. Pat. No. 3,324,782,

construction 16. The plenum construction 16 is adapted to receive the air and distribute same through a plurality of ducts 18 to each of the zones to be treated. In the form of plenum construction illustrated in FIG. 1, there are six ducts connected to each side of the plenum construction for forwarding air to each of 12 separate zones. it will be understood that the interior construction of the plenum construction may be altered in order to accommodate a lesser number or a greater number of zones. Commonly, the plenum construction 16 will be constructed and arranged to ac commodate either 12 or 18 ducts.

Turning now to FIG. 2, there is shown a plenum construction 116 embodying principles of the present invention. The plenum construction 116 is comprised of a housing having a plurality of chambers a, b, c, d, e, f and 8 formed therein. The housing of the plenum construction 116, is defined basically by sides 120, 122, bottoms 123, 125 and end walls 124, 126. Common divider wall means 128, 129, 130, 131, 132 and 133 are provided in the housing between the front wall or side wall 120 and the rear wall or side wall 122 and extend generally parallel to the end walls 124, 126. The divider wall 133 between the compartments or chambers f and 3 extends generally from the level of the top of the sides 120, 122 and end wall 126 to the plan or base or bottom 125. Chamber g is thus rectangular in cross-section and is typical of a chamber or compartment in a prior known plenum construction. The remaining chambers a, b, c, d, e, and fare constructed and arranged to embody the principles of the present invention.

Turning specifically to chambers a and b, for example, each is comprised of an entry portion at the top b. Air is communicated from the duct 146 to an area to be treated.

Similarly, air entering the compartment b will pass downwardly over the inclined surface means comprised of the inclined wall 150 and the portion 123b of the bottom wall 123 of the plenum construction 116. The air will pass beneath the partition or divider wall 128 and thus be discharged into the duct 142. It will be understood that the inclined wall portion 143 provides a common wall between the compartments and b. The inclined wall 150, which extends downwardly from the wall 122 toward the side 120 to its merger along the apex 144 with the inverted V of the bottom 123, also thereof and a discharge portion at the bottom thereof.

The entry portion is defined between the end wall 124, the common divider wall 128, and side wall 120, the side wall 122, and the apex of the inverted V-shaped bottom 123 of the major portion of the housing of the plenum construction, namely the bottom of chambers a-f. The discharge portion is substantially equal in length to the sum of the lengths of the entry portions to compartments a and b. lt will be understood that the compartments a and b cooperate in adjacent pairs, namely a and b; c and d; e andf.

Turning now to FIGS. 3, 4, 5 and 6, there is illustrated further details of the plenum construction 116. The upper entry portion of each compartment a, b, c, d, e, f, and g cooperates with complementary compartments in the air outlet portion of the air treating unit 10. Air entering the compartment a will pass down the streamlined inclined surface means to a discharge opening in wall 122 that communicates with a duct 142 which is substantially the same cross-section as the sum of the widths of the entry portions to the compartments a and b. The inclined surface means in the compartment a includes an inclined wall portion 143 sloping downwardly from the side 120 toward the side 122. The inclined wall portion 143 intersects at 144 withthe apex of the inverted V-shaped bottom wall 123. The inclined wall means is comprised of the wall portion 143 and bottom portion 1230 which merge smoothly one with the other. Thus, air entering the compartment a will pass in a streamlined path over the inclined surfaces 143, 123a to the discharge duct 146. The entry portion to compartment a is the width between the dividers 124 and 128 and the width of the discharge portion is the combined widths of the compartments a and provides a common wall between portions of the adjacent compartments 0 and b. Air is discharged from compartment b through opening is side 120 into duct 142.

As illustrated, the compartments 0 and d are identical to the compartments a and b. Compartments b and c are divided one from the other by a partition 128, which extends from the top into contact with the bottom wall portions 123a and 123b so as to provide a full divided area between compartments b and c. The inclined wall 152 is constructed in the same fashion as the inclined wall 143 of compartment a. Wall 152 merges with the apex 144 and the portion 123, of the bottom wall 123 so as to carry air entering compartment 0 in a smooth path into the discharge duct 154. Air entering compartment d passes smoothly over the inclined surface 156 which merges at the apex with the bottom wall portion 123b and the air then passes into the discharge portion of the chamber d which extends the distance between walls 129 and 131 to convey air through opening 151 into the discharge duct 158 for transmission to an area to be treated.

With reference to compartments e and f, it is seen that the relative width of compartments in the plenum construction may be altered. As illustrated, the entry portion of compartment e is approximately one-half the width of the entry portion of compartment f. Air entering compartment e passes downwardly over the inclined surface 160 which merges at the apex with the bottom wall 123a. Air passes through the area between the divider wall 132 and the bottom wall 1230, which extends to the partition wall 133 and is discharged from the plenum construction to duct 162.

Air entering compartment f flows downwardly over inclined surface 164 extending from the wall 122 downwardly to a smoothly merging engagement at apex 144 with the bottom wall portion 123b. Air passes through the opening between the divider wall 132 and the bottom 123b and discharges from compartment f through opening 165 to duct 166 to an area to be treated. The inclined wall 160 forms a common wall between compartments e and f. Similarly, inclined wall 164 forms a common wall between compartments e and f. The outlet openings from the compartments e and f are each substantially equal to the sum of the widths of the compartments e and f between partition walls or divider walls 131 and 133.

Air entering compartment g from the air treating unit 10 will pass into duct 168 for transmission to a selected area to be conditioned.

With reference to FIG. 6, there is seen a cross-section of the plenum construction 1 16 taken through the compartments c and d. The partition wall 131 extends downwardly into engagement with both the portions 123a and 123!) of the bottom 123 so as to provide a full divider between compartments d and e. The inclined wall surface 156 inclines downwardly from wall 122 until it engages the bottom wall 123 at the apex 144. Thus, a smooth inclined surface is provided so that air entering the entry portion of the compartment (1 may flow downwardly over the wall 156 and then over the wall portion 123 which extends between dividers 129 and 131 into the discharge duct 158. The top surface of the inclined wall means 156 forms a part of the compartment d and the bottom surface of the inclined wall 156 forms a part of the compartment 0. By virtue of the streamlined air flow over the inclined wall means comprising wall portion 156 and bottom portion 123b, there is no velocity pressure loss of the air in compartment d. Similarly, by virtue of the construction wherein the outlet is substantially equal to the sum of the widths of the combined inlet portions of the adjacent pairs of compartments, there is ample width by means of which adjacent ducts can be affixed to the plenum construction 116.

A further advantage of the present invention is seen in FIG. 7, which shows a modified plenum construction 116' taken substantially along the same line as FIG. 6. FIG. 7 shows a duct 154 extending from the bottom wall portion 123a of compartment c rather than from the end wall or side wall 122. It will be understood that the duct 154' will be'disposed beneath the duct 158 and that in all other respectsthe constructions are the same. The ducts that would connect to side 122 will instead connect to bottom wall portion 123a and extend generally beneath the duct from an associated compartment. The plenum construction 116' of FIG. 7 may be utilized where there is insufficient space between the wall 122 and a wall of a building, for example, to permit ducts to be secured to the wall 122.

In FIG. 8, there is shown an exploded perspective view of the plenum construction 116. It will be observed that the wall members 133, 126 are formed integrally with the bottom 125 from a single piece of sheet metal bent into form. The base or bottom 125 is provided at each end with a flange 125a to permit affixation to the side walls 120, 122. Wall 133 includes flanges 133a and 13311 extending inwardly toward the wall 126 for helping to position the divider wall 133 relative to the side walls 120, 122. The upper end of the wall 133 is downwturned so as to minimize the chance of cutting or nicking of the installers hands by the sharp edge of the metal. The end wall 126 includes flanges 126a and 126b facing toward the wall 133for securing the end wall 126 in place relative to walls 121, 122.

The body portion or housing of the plenum construction is formed integrally from a single piece of metal formed to define the generally parallel walls 120 and 122 and an inverted generally V-shaped bottom 123. The upper edges of the walls 120 and 122 are bent over to form a flange which provides protection against injury to the fabricator and/or installer also stiffening reinforcement lengthwise of the housing of the plenum construction 116. The end wall 124 is fabricated from a plate member having a downturned upper end to provide for protection from cutting and includes flanges 124a and 124b extending toward the end wall 126 and permitting affixation of the end wall 124 to theside walls 120,122. A V-shaped notch is .provided in the wall 124. Flanges 1124c and 124d extend from wall 124 and define the notch. The flanges 124C and 124d are adapted to be secured to the wall portions 123a and 123!) of the bottom 123, for example by spot welding.

The divider walls and inclined walls are preferably formed as a subassembly as indicated in FIGS. The inclined walls 143 and 151) and the common dividing wall 128 are stamped and then formed to shape from a single sheet metal member. The flange a extending upwardly from the inclined wall portion 150 is adapted to be secured to the divider wall 129. Flange 143a is adapted to be connected to end wall 124.

The inclined wall portion 129, the inclined wall portion 156 and the common divider wall 131) are similarly formed from a single piece of sheet metal. Flange 129 is adapted to be connected to wall 120, for example by spot welding. The flange 152a of the inclined wall 152 is adapted to be secured to the divider wall 129. The flange 156a is adapted to be suitably secured, as for example by spot welding, to the divider wall 131. The divider wall 131 includes a flange 131a adapted to be secured to the wall 122, flange 131b that is adapted to be secured to the wall portion 123a of the bottom 123, and flange 1310 that is adapted to be connected to wall 120. It will be noted that the divider wall 131 is generally triangular in configuration and extends from the top level of the side walls 120, 122 to the bottom soas to provide a full divider wall between the compartments d and e to block any air flow between the two compartments. The inclined wall 160, the common divider wall 132 and the inclined wall 164 are formed from a single member suitably formed. The flange 160a is secured to the divider wall 131 and flange 1640 is adapted to be connected to the wall 133.

In fabrication of the embodiment illustrated in FIGS. 2-6 the end wall portions defining the compartment g will be formed to shape, the end wall 124 will be formed to shape, and the center portion of the housing comprising the sides 120, 122 and the bottom 123 will be suitably formed. The components of the subassembly comprising the divider walls and inclined walls are fabricated andassembled as indicated. The subassembly is then inserted into the housing and the parts are spot welded one to the other to provide the finished assembly. The work can readily be done in a factory and if necessary, can also be done in the field by suitably skilled sheet metal workers.

Turning now to FIG. 9, there is illustrated a further embodiment of the present invention wherein the housing of plenum construction 216 is divided into twelve separate compartments of equal width. Each pair of .compartments j, k; I, m; n, 0; p, q; r, s; t, u are constructed and arranged in a fashion similar, for example, to compartments a, b in the modification of FIGS. 2-6. The plenum construction 216 includes end walls 224, 226, sides 2211, 222, and bottom 223. Alternate divider members 231, extend from the top level of the sides 220, 222 and end walls 224, 226 to the bottom of the housing and alternate divider walls 226 which extend from the top and have a generally triangular configuration corresponding to the incline of the incline wall portions 243 and 2511. It will be understood by reference to FIG. 10 that the inclined wall portions 243 and 2511 are adapted to cooperate with one another and with the wall portion 228 to define the adjacent compartments wherein the entry portion to each will be disposed between a pair of adjacent dividers, whereas the discharge portion will be substantially equal to the sum of the widths between two adjacent compartments. Thus, the air entering compartment j may be discharged from the duct 260, whereas the air entering the compartment k may be discharged from a duct connected to the wall 222 (not shown). The width of the duct 260 is substantially equal to the width of the compartments] and k. Similarly, the air entering the entry chamber of compartment 1 will be discharged into the duct 262 which is substantially equal in width to the combined widths of the compartments I and m. The construction will be repeated for each of the six pairs of compartments or the 12 compartments illustrated in FIG. 9 so as to provide an arrangement wherein the air can be discharged over a streamlined surface with minimum velocity pressure loss.

By virtue of the present invention the loss of velocity pressure is materially minimized if not eliminated, and the fan for moving air through the plenum construction is able to run slower and quieter in order to effect desired air movement. A large outlet opening is provided from pairs of compartment, and flow through the compartments is streamlined and smooth, with no unnecessary restrictions. In some instances, a smaller fan motor or a fan motor having less horse power can be utilized to effect the desired air movement.

ln one embodiment of the invention wherein there are eighteen zones to be treated, or eighteen like compartments in the plenum construction, there are nine outlets connected to each side wall. Each outlet is about 9% inches wide and about inches high. Such outlets will nicely handle return air velocities on the order of 1,000 feet per minute, which is a common design criteria.

The new plenum construction is simple to manufacture and thus relatively inexpensive. The plenum construction of the present invention has great utility in that, as seen from the embodiment of FlG. 7, it can be placed against the wall or close to obstructions in a building and still provide duct connections to two different surfaces by virtue of the bottom having an inverted V-shaped configuration.

While there has been described presently preferred forms of the present invention, it will be understood by those skilled in the art that the invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. A plenum construction for receiving air from an air treating unit and distributing same to a plurality of zones to be treated comprising a housing having at least a pair of chambers defined therein by common divider wall means, end wall means, side wall means, bottom wall means and inclined wall means in each chamber extending from a side wall means toward the opposite side wall means, each inclined wall means forming a common wall between the chambers, each chamber communicating with the air treating unit and including an entry portion and a discharge portion, the length of each discharge portion being substantially equal to the sum of the lengths of the inclined walls in each chamber, an outlet being formed in the housing substantially equal in length to the discharge portion of each chamber, the bottom wall means being generally an inverted V in cross-section, and wherein one inclined wall means extends from one side wall means and intersects with the apex of the bottom wall means, the other inclined wall means extends from the other side wall means and intersects with the apex of the bottom wall means, said divider wall means being coterminus with the ends of the inclined wall means, whereby air entering each chamber may pass smoothly over the inclined wall means and exit from the plenum construction through said outlet that is substantially the length of the discharge portion of the chamber.

2. A plenum construction as in claim 1 wherein said outlet is formed in the side wall means.

3. A plenum construction as in claim 1 wherein the outlet from one chamber is formed in the side wall means and the outlet from the other chamber is formed in the bottom wall means.

4. A plenum construction as in claim 1 wherein the inclined wall means in one chamber includes a flange portion for securing same to an end wall means, and an inclined portion that is formed integrally with the divider wall means.

5. A plenum construction as in claim 1 wherein the length of each discharge portion is substantially equal to the sum of the inlet portions to the pair of chambers.

6. A plenum construction as in claim 1 wherein the side wall means are upright and parallel to one another, the end wall means and divider wall means being upright and being disposed perpendicular to the side wall means.

7. A plenum construction as in claim 6 wherein the inclined wall means and the divider wall means are formed as a subassembly insertable as a unit into the housing comprised of the side wall means, end wall means and bottom wall means.

8. A plenum construction for receiving air from an air treating unit and distributing same to a plurality of zones to be treated comprising a housing having at least a pair of chambers defined therein by common divider wall means, end wall means, side wall means, bottom wall means and inclined wall means in each chamber extending from a side wall means toward the opposite side wall means, each inclined wall means forming a common wall between the chambers, each chamber communicating with the air treating unit and including an entry portion and a discharge portion, the length of each discharge portion being substantially equal to the sum of the lengths of the entry portions of adjacent chambers, an outlet formed in a housing, one inclined wall means extending from one side wall means and intersecting with the apex of the bottom wall means, the other inclined wall means extending from the other side wall means and intersecting with the apex of the bottom wall means, said divider wall means being coterminous with the ends of the inclined wall means, whereby air entering each chamber may pass smoothly over the inclined wall means and exit from the plenum construction through said outlet. 

1. A plenum construction for receiving air from an air treating unit and distributing same to a plurality of zones to be treated comprising a housing having at least a pair of chambers defined therein by common divider wall means, end wall means, side wall means, bottom wall means and inclined wall means in each chamber extending from a side wall means toward the opposite side wall means, each inclined wall means forming a common wall between the chambers, each chamber communicating with the air treating unit and including an entry portion and a discharge portion, the length of each discharge portion being substantially equal to the sum of the lengths of the inclined walls in each chamber, an outlet being formed in the housing substantially equal in length to the discharge portion of each chamber, the bottom wall means being generally an inverted V in cross-section, and wherein one inclined wall means extends from one side wall means and intersects with the apex of the bottom wall means, the other inclined wall means extends from the other side wall means and intersects with the apex of the bottom wall means, said divider wall means being coterminus with the ends of the inclined wall means, whereby air entering each chamber may pass smoothly over the inclined wall means and exit from the plenum construction through said outlet that is substantially the length of the discharge portion of the chamber.
 2. A plenum construction as in claim 1 wherein said outlet is formed in the side wall means.
 3. A plenum construction as in claim 1 wherein the outlet from one chamber is formed in the side wall means and the outlet from the other chamber is formed in the bottom wall means.
 4. A plenum construction as in claim 1 wherein the inclined wall means in one chamber includes a flange portion for securing same to an end wall means, and an inclined portion that is formed integrally with the divider wall means.
 5. A plenum construction as in claim 1 wherein the length of each discharge portion is substantially equal to the sum of the inlet portions to the pair of chambers.
 6. A plenum construction as in claim 1 wherein the side wall means are upright and parallel to one another, the end wall means and divider wall means being upright and being disposed perpendicular to the side wall means.
 7. A plenum construction as in claim 6 wherein the inclined wall means and the divider wall means are formed as a subassembly insertable as a unit into the housing comprised of the side wall means, end wall means and bottom wall means.
 8. A plenum construction for receiving air from an air treating unit and distributing same to a plurality of zones to be treated comprising a housing having at least a pair of chambers defined therein by common divider wall means, end wall means, side wall means, bottom wall means and inclined wall means in each chamber extending from a side wall means toward the opposite side wall means, each inclined wall means forming a common wall between the chambers, each chamber communicating with the air treating unit and including an entry portion and a discharge portion, the length of each discharge portion being substantially equal to the sum of the lengths of the entry portions of adjacent chambers, an outlet formed in a housing, one inclined wall means extending from one side wall means and intersecting with the apex of the bottom wall means, the other inclined wall means extending from the other side wall means and intersecting with the apex of the bottom wall means, said dividEr wall means being coterminous with the ends of the inclined wall means, whereby air entering each chamber may pass smoothly over the inclined wall means and exit from the plenum construction through said outlet. 